1. Field of the Invention
The present invention relates in general to seats, and more particularly, to vehicular seats of a reclining type which comprises a seat portion, a seatback portion and a reclining device.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional vehicular seat of the reclining type will be outlined with reference to Fig. 3 of the accompanying drawings.
The vehicular seat 1 comprises generally a seat portion 2, a seatback portion 3 and a reclining device 4.
The seatback portion 3 comprises a rectangular seatback frame 5 constructed of metal pipe, side metal plates 6 secured to side portions 5a of the frame 5, a plurality of S-shaped springs 8 extending between the side portions 5a of the frame 5 and a rectangular cushion pad 9 covering the entire of the frame assembly.
The reclining device 4 functions to vary the angular position of the seatback portion 3 relative to the seat portion 2. The device 4 shown in the drawing comprises two arms 4a (only one is shown) which are secured to the side metal plates 6 and pivotally connected to the seat portion 2 through known pivot mechanisms. A latch mechanism controllable by a handle 4b is incorporated with one of the pivot mechanisms for latching the seatback portion 3 at a desired angular position relative to the seat portion 2.
However, the conventional vehicular seat 1 as described hereinabove has the following drawback due to its inherent construction.
That is, when a person sits on the seat 1 with his back in contact with the seatback portion 3, his lumbar portion is uncomfortably pressed by a lower part of the seatback portion 3. This undesired phenomenon becomes much severe when the seatback portion 3 assumes a largely backward inclined position. This is because of presence of the lower horizontal portion 5b of the rectangular seatback frame 5, which swings forward upon backward inclination of the seatback portion 3.
Furthermore, due to restriction in function and design of the reclining device 4, there is a limit in increasing the thickness of the cushion pad 9 at the area which covers the lower horizontal portion 5b of the seatback frame 5.